Remove leading / from snap path in dev/shm as the DEFAULT_DEVSHM already includes it - lead to doubling the //.
Fix redirected /dev/shm path from doubling the /dev/shm/ prefix - lead to cases where shm path would be: /dev/shm/snap.snapname./dev/shm/originalshmname
Remove leading / from snap path in dev/shm as the DEFAULT_DEVSHM already includes it - lead to doubling the //. Fix redirected /dev/shm path from doubling the /dev/shm/ prefix - lead to cases where shm path would be: /dev/shm/snap.snapname./dev/shm/originalshmname